The invention relates to a method of monitoring the operation of a wind energy plant, wherein the operation comprises collection of blade-related operational data. Novel aspects of the method according to the invention comprises that, in predefined points on the blade, position indicators are arranged that can be used in a positioning system for identifying the position of the position indicators; and that the positions of the position indicators and hence the position of the predefined points are determined and collected as a part of said blade-related operational data.